The present invention relates generally to a device or tool for cleaning filter elements and is particularly concerned with a device for cleaning the air filters of automobiles and other types of vehicles or industrial engines.
Automobiles and other vehicles and machines having similar engines typically employ folded paper types of air cleaners for filtering dust and other particles from air entering the engine. In ordinary use these filters become clogged with accumulated dust and dirt, potentially choking off air supply to the engine, reducing power and increasing fuel consumption. Dirt may even be forced through the filter into the engine, causing damage to moving parts. Thus, air filters require replacement or cleaning on a regular basis. When the engine is in use under extreme conditions, for example vehicles used in a desert or an otherwise extremely dusty environment, frequent replacement or cleaning of the filters is needed. Since replacement is relatively expensive, it would be advantageous if the folded paper filter could be cleaned effectively to avoid the need for frequent replacement.
In the past, folded paper air filters for engines of various types have often been replaced when clogged, involving significant expense, or have been cleaned simply by directing an air hose at the filter element to blow out any loose particles or dust. However, the air blast from a standard high pressure air line is so powerful that it often damages the relatively fragile filter paper, requiring replacement. U.S. Pat. No. 3,733,639 of Timian describes such an arrangement, in which the filter unit is placed in an enclosure and an air hose extends into the enclosure into the center of the filter unit. A revolving air distributer in the form of a tubular element directed towards the filter element is connected to the inner end of the air line. Thus, a powerful blast of air is directed against the inner side of the annular filter element.
In my U.S. Pat. No. 5,182,832, a tubular member has a head rotatably mounted at one end, and an air hose can be secured at the other end. The head has small outlet openings spaced around its periphery for directing air flow outwardly across the inner side of an annular air filter unit. This tends to dislodge dirt without damaging the filter. However, this device can be difficult to handle and incorporates a press fit bearing which could potentially blow off under extreme conditions.
It is an object of the present invention to provide a new and improved air filter cleaning device.
According to the present invention, an air filter cleaning device is provided which comprises an elongate handle having a through bore, a connector at one end of the handle for connecting the handle through bore to an air supply hose, and an enlarged rotary head rotatably mounted on the opposite end of the handle. The rotary head has an internal air distribution chamber connected to the outlet end of the handle through bore, and three distribution outlets on the outer periphery of the head for directing air flow towards an air filter unit.
The head includes a rotor arrangement for re-directing air flow through the head so that the head is rotated relative to the inlet tube and air flow from the outlets directed across the entire area of an annular air filter unit surrounding the head. In one embodiment of the invention, the rotor arrangement comprises a series of angled rotor passageways in the peripheral wall of the chamber for directing air flow in a circular path from the chamber and thus spinning the head in the opposite direction to the air flow, in a turbine-like manner. In an exemplary embodiment, the head is generally cylindrical and the chamber is hollow, and the rotor passageways extend in a generally tangential direction relative to the chamber. The air outlets extend radially outwardly from the chamber to direct air onto a surrounding annular air filter, for example. By reducing the air flow and directing it out of a number of small outlets, the device can be connected to a standard high pressure air line while risk of damage to the filter paper of the air filter unit is reduced. At the same time, the variation in air pressure against the pleated or folded paper of the air filter unit as the head rotates will cause flapping of the paper, tending to dislodge any dirt or dust so that it can be blown off relatively easily.
In an exemplary embodiment, the rotary head has an inlet opening through which the second end of the handle extends, and a sealed radial bearing has an inner race secured to the second end of the handle, and an outer race secured to the inner wall of the chamber. The chamber may have a reduced diameter upper end portion in which the bearing is mounted, and the remainder of the chamber may be of larger diameter. Air flow is directed downwardly into the enlarged portion of the chamber and will flow outwardly through the air distribution outlets and rotor outlets.
This device allows an engine air filter to be cleaned without damaging the filter, using a standard air hose with the rotating head attached to diffuse the air flow and reduce the air velocity so that the relatively fragile filter paper is not damaged. This extends the lifetime of both vehicular and industrial engine filter units substantially, reducing maintenance costs and conserving materials. The elongate handle may have gripping surface for easy handling and use. The sealed bearing is more reliable, and is mounted securely to the handle and rotary head to reduce the risk of separation of the parts under extreme conditions.